The problem can also be caused by an unsupported USB device being attached, or because the printer is plugged into a USB hub according to this document. If you've tried all the steps in that document, then you will need to replace the printer. If you're in warranty, HP should replace the printer for you. Check your warranty here. You can reach HP tech support by calling 1-800-474-6836 in the US and Canada, international users click here.